Unit 2 Energy and Gases

Question 1

What is energy?

Answer 1

The ability of a physical system to perform work

Question 2

What is the first law of thermodynamics?

Answer 2

Energy can neither be created nor destroyed, only transformed

Question 3

All types of energy fall under ___

Answer 3

kinetic and potential energy

Question 4

What is kinetic energy?

Answer 4

the energy of motion

Question 5

formula for kinetic energy

Answer 5

KE= 1/2 mv2

Question 6

the higher the temperature, the greater __

Answer 6

KE

Question 7

What is heat (q)?

Answer 7

the transfer of KE from a substance at a higher temp to a system at a lower temp

Question 8

What are common forms of energy?

Answer 8

mechanical, heat, bond, light, and electrical

Question 9

What is the Kelvin scale?

Answer 9

Developed from William Thomson, a temperature scale that begins at 0 and always is a + number

Question 10

How do you find K from C if the number is measured past the ones place?

Answer 10

C + 273.15

Question 11

How do you find K from C if the number is whole?

Answer 11

c + 273

Question 12

What does potential energy depend on?

Answer 12

attraction and repulsion

Question 13

What is chemical energy?

Answer 13

The potential energy that’s made available during a chemical reaction where bonds are broken and formed

Question 14

When bonds form, energy is _

Answer 14

released. Freed to Form!

Question 15

When bonds are broken, energy is _

Answer 15

required. Takes to Break

Question 16

What is an endothermic reaction?

Answer 16

when heat is absorbed by the process (indicates positive enthalpy). Transferred from surroundings to system

Question 17

What is an exothermic reaction?

Answer 17

When heat is lost, indicating negative enthalpy. Heat transferred from the system into the surroundings

Question 18

What is enthalpy?

Answer 18

the amount of heat energy lost or gained by a system during a process at constant process

Question 19

What happens as a solid is heated?

Answer 19

the particles vibrate faster and faster until they have enough energy to break away from their fixed positions

Question 20

What happens as a liquid cools?

Answer 20

the particles lose energy and move more and more slowly. When they settle in fixed positions, the liquid has frozen or solidified

Question 21

The volume of liquids and solids are

Answer 21

fixed

Question 22

What is the kinetic molecular theory of gases

Answer 22

A theory that helps us understand why gases behave the way they do and gives us insight into the behavior of solids and gases.

Question 23

Gases are mostly empty space because

Answer 23

they consist of molecules whose separation is much larger than the size of the molecules themselves

Question 24

What path and direction to particles in gases move?

Answer 24

Straight and random

Question 25

Describe the collisions of gas particles.

Answer 25

Frequently with sides of the container and less frequent with each other. Elastic, meaning no energy is gained or lost, only transferred

Question 26

Do particles of a gas attract or repel each other?

Answer 26

No

Question 27

KE is proportional to (x) in a gas

Answer 27

temp

Question 28

The kinetic molecular theory of gases applies to

Answer 28

ideal gases

Question 29

Be sure to study phase diagrams.

Answer 29

Ok

Question 30

What is critical temperature?

Answer 30

above this temperature, a gas cannot be liquified

Question 31

What is critical pressure?

Answer 31

The pressure at critical temperature

Question 32

What is the triple point?

Answer 32

The point at which 3 states exist

Question 33

What is Boyle's Law?

Answer 33

P1V1 = P2V2. When pressure increases, the volume decreases and vice versa. Inverse. Make sure to study the graphs in the notes.

Question 34

Charles' Law

Answer 34

V1 / T1 = V2 / T2. When temp. increases, the volume increases. Direct.

Question 35

The temperature must be in Kelvin whenever you...

Answer 35

use the gas laws

Question 36

What is Gay Lussac's law?

Answer 36

P1 / T1 = P2 / T2. When the temperature increases, the pressure increases. Direct.

Question 37

What is Avogadro's Law?

Answer 37

V1 / n1 = V2 / n2. The volume and amount of gas varies directly. Equal volumes of gases at the same temp and pressure contain equal numbers of particles, even if gases are different.

Question 38

What is Dalton's law of partial pressure?

Answer 38

The total pressure of a mixture of gases is simply the sum of the individual pressures of each of the gases (known as partial pressures)

Question 39

When do you use Dalton's Law of Partial Pressure?

Answer 39

when you have a mixture of 2 or more gases which do not react chemically

Question 40

When does Dalton's law hold true?

Answer 40

when the pressures you are adding together were all recorded at the same temperature and volume conditions

Question 41

Equation for Dalton's law

Answer 41

Ptotal = Pa + Pb + Pc...etc

Question 42

The pressure of a gas collected over water is a combo of...

Answer 42

the pressure of the gas and the pressure of the water vapor

Question 43

If you see the words "over water" in a problem, you must ...

Answer 43

subtract the water vapor pressure from the total pressure of the gas collected over the water

Question 44

Formula for the Ideal Gas law

Answer 44

PV = nRT